Size Guide for Silicone Toys: How to Find the Perfect Fit
Size is the most speculated about and least factually discussed topic. Buying too large out of false ambition. Buying too small out of false modesty. Both lead to the same disappointment. This guide explains how to find the right size – based on anatomy, material behavior, and honest self-assessment.
Why size is more complex than length and diameter
Most buyers look at two numbers: length and diameter. That's a start – but it's not the complete answer. What you actually feel depends on four factors:
- Usable length – not the total length, but how much of it is actually inserted
- Diameter progression – uniform, progressive, or with constrictions?
- Shore hardness – soft material feels smaller than hard material at the same diameter
- Shape – straight, curved, with glans geometry or without?
An 18 cm dildo made of Shore A 15 feels different from the same dildo made of Shore A 30. A uniform shaft feels different from a progressive one. Size is a system – not a single number.
Step 1: Determine your starting size
If you don't have a reference product yet, start with what you know. Fingers are a reliable starting point:
| Reference | Approximate Diameter | Recommended Entry |
|---|---|---|
| 1 Finger | ~1.5–2 cm | Very slender toys, beginner anal |
| 2 Fingers | ~3–3.5 cm | Slender toys, beginner vaginal |
| 3 Fingers | ~4–4.5 cm | Medium toys, comfortable entry |
| 4 Fingers | ~5.5–6 cm | Larger toys, experienced users |
Important: These values are guidelines, not limits. Anatomy varies. Arousal changes perception. Lube changes resistance. Start conservatively – you can always go bigger, but you can't undo a bad first experience.
Step 2: Correctly estimate length
Length is the most overestimated measurement. The average vaginal depth in an unaroused state is 7–10 cm, and in an aroused state, 10–15 cm. Most people use 12–16 cm of a toy – anything beyond that is optional.
What usable length means
For toys with a suction cup or wide base, the usable length is shorter than the total length. For a 20 cm toy with a 3 cm base, 17 cm are usable – that's the relevant number. We provide both measurements for all products.
Length by experience level
- Beginner: 12–15 cm usable length – sufficient for G-spot stimulation, no risk of overstretching
- Advanced: 15–18 cm – full depth stimulation, prostate reachability
- Experienced: 18–22 cm+ – conscious decision for deep sensation, requires experience and patience
Step 3: Consider diameter and Shore hardness together
This is where the most common mistake lies: choosing diameter without Shore hardness. A toy with a 4.5 cm diameter made of Shore A 15 feels significantly smaller than the same toy made of Shore A 30 – because soft material gives way under pressure and adapts.
| Shore Hardness | Felt Diameter | Recommendation |
|---|---|---|
| Shore A 10–15 | Significantly smaller than measured | For those who prioritize softness over structure |
| Shore A 20–25 | Slightly smaller than measured | Optimal balance – our most chosen range |
| Shore A 30–35 | Corresponds to measured | For those who prefer defined structure and texture |
| Shore A 40+ | Can appear larger than measured | For experienced users with a clear preference for firmness |
→ The full explanation of the Shore scale: Shore hardness in silicone toys explained
Step 4: Choose shape and function
Straight vs. curved
Straight toys are more versatile – they work in more positions and for more applications. Curved toys are more precise – they hit the G-spot or prostate more reliably, but require less active steering. If you're unsure: start straight, switch to curved when you know what you're looking for.
With or without glans geometry
Toys with pronounced glans geometry create a defined pressure point during insertion and removal. For many, this is the most intense moment. For beginners, this pressure point can be surprising – a slender toy without a pronounced glans is a gentler introduction.
Texture: when it helps, when it hinders
Textures – ribs, nubs, vein structures – enhance stimulation during movement. With too little experience or too little lubricant, they can create friction instead of stimulation. Rule of thumb: The more experience, the more texture. Beginners are better off starting with smooth or lightly textured surfaces.
Size recommendations by product category
Realistic Dildo – for an anatomically familiar experience
SilikonLust's realistic dildos are available in several sizes. The natural curvature hits the G-spot or prostate without active steering – making them particularly suitable for beginners seeking targeted stimulation.
→ Discover the Realistic Dildo Collection
BBC Dildo – for those who consciously want more
BBC dildos are not toys for beginners – they are a conscious decision for intensity. The combination of above-average size and realistic anatomy requires experience, patience, and sufficient lubricant. Those who use them correctly experience a stimulation profile that smaller toys cannot achieve.
→ Discover the BBC Dildo Collection
Fantasy Dildo – when geometry is more important than size
With fantasy dildos, the diameter progression is often more important than the maximum size. Progressive structures – knots, rings, asymmetrical geometries – create stimulation through pressure variation, not sheer size. A fantasy dildo with a 3.5 cm maximum diameter can be more intense than a straight dildo with 5 cm.
→ Discover the Fantasy Dildo Collection
The most common sizing mistakes – and how to avoid them
- Too big for the first purchase: The most common mistake. Size can be worked up to – a bad first experience lingers. Start one size smaller than you think.
- Prioritizing length over diameter: Diameter determines the feeling of fullness. Length determines depth. For most, diameter is the more relevant parameter.
- Ignoring Shore hardness: A soft toy feels smaller at the same diameter. Those who switch from a soft to a hard toy often experience a surprise.
- Not planning for lubricant: Lubricant significantly changes perceived size. Always use water-based lubricant – silicone-based lubricant can damage platinum silicone long-term.
Read more: Everything you need to know before buying
- Fantasy vs. Realistic: Which toy is right for you?
- Shore hardness in silicone toys explained
- What is platinum silicone? Material, manufacturing, and body feel
- Cleaning silicone toys: The complete disinfection guide
Frequently Asked Questions
What size is recommended for beginners?
For vaginal use: 12–15 cm length, 3–4 cm diameter, Shore A 20–25. For anal use: start shorter and slimmer – 10–12 cm, 2.5–3.5 cm diameter. More important than precise measurements: sufficient lubricant and no rush.
Is length or diameter more important?
For most people, diameter is the more relevant parameter – it determines the feeling of fullness and pressure on the walls. Length determines the depth of stimulation. If you have to choose between two toys: choose the diameter that suits your experience, and the length you can safely use.
Why does a soft toy feel smaller than a hard one of the same diameter?
Soft material (low Shore hardness) gives way under pressure and adapts. The effective resistance is less than the measured diameter. Hard material does not give way – the measured diameter corresponds to the felt one. At the same measurement, Shore A 15 feels significantly smaller than Shore A 35.
Can I switch to larger toys over time?
Yes – with patience and regularity. The body gets used to size if given time. Don't jump from small to large in one go. Gradually increase the diameter – 0.5 cm per step is a realistic pace. Length is less critical than diameter.
Which lubricant is suitable for platinum silicone toys?
Exclusively water-based lubricant. Silicone-based lubricants can long-term damage the surface of platinum silicone. Water-based lubricant is fully compatible, protects the material, and is easy to wash off.
